Relationship between anxiety and concussion symptoms among adolescents enrolled in a randomized controlled trial of aerobic exercise

BACKGROUND: Affective symptoms, specifically, anxiety, are often overlooked after sport-related concussion (SRC), and may contribute to prolonged recovery. OBJECTIVE: To examine the impact of anxiety during clinical recovery among adolescents (13-18y) enrolled in a randomized trial of aerobic exercise for SRC. METHODS: Patients at three sites were randomized into aerobic exercise or stretching arms, and enrolled in the 4-week intervention. The relationship between PROMIS Anxiety score at initial visit and time to symptom resolution was evaluated with survival analysis. The relationship between weekly PROMIS Anxiety score and Post-concussion Symptom Inventory (PCSI) score was evaluated with Linear Mixed Models. Analyses adjusted for study arm and baseline covariates. RESULTS: Among 54 adolescents (median age=15.8y, initial visit PCSI score=32, pre-injury PROMIS Anxiety score=2), median time to symptom resolution was 10 days (25th-75th percentiles: 6-24) in the Low-PROMIS Anxiety group and 12 days (25th-75th percentiles: 5-21) in the High-PROMIS Anxiety group (p=0.62). Each additional unit of PROMIS Anxiety score corresponded to a 1.52-unit higher PCSI total score (p< 0.01). Neither effect varied by aerobic exercise/stretching group. CONCLUSION: Higher initial PROMIS Anxiety score was not significantly associated with delayed symptom resolution. However, over time, PROMIS Anxiety score was significantly associated with elevated PCSI score, regardless of exercise/stretching group.